Mathematics · Textbook solutions
Conic Sections
Every solved example, exercise, and miscellaneous question, in the order the textbook teaches them. · 179 questions
7.1 Parabola
8 q
Solved Examples
Worked · 8
- Find the coordinates of the focus, equation of the directrix, length of latus rectum and coordinates of end points of latus rectum of each of the following parabolas.7.1.10 SolvedEx.1(i)
- 7.1.10 SolvedEx.1(ii)
- 7.1.10 SolvedEx.2Find the equation of the parabola with vertex at the origin, axis along Y-axis and passing through the point
- 7.1.10 SolvedEx.3Find the equation of the parabola whose diretrix is
- 7.1.10 SolvedEx.4Calculate the focal distance of point P on the parabola whose ordinate is 10
- 7.1.10 SolvedEx.5Find the equation of the parabola having as one of extremities of porabola.
- 7.1.10 SolvedEx.6For the parabola , find the parameter of the point
- 7.1.10 SolvedEx.7Find the coordinates of the vertex and focus, the equation of the axis of symmetry, diretrix and tangent at the vertex of the parabola
7.1 Tangents to a Parabola
3 q
Solved Examples
Worked · 3
- 7.1.13 SolvedEx.1Find the equation of tangent to the parabola at .
- 7.1.13 SolvedEx.2Find the equation to tangent to the parabola from the point .
- 7.1.13 SolvedEx.3Show that the tangents drawn from the point to the parabola are perpendicular to each other.
Exercise 7.1
28 q
- Find co-ordinate of focus, equation of directrix, length of latus rectum and the co-ordinate of end points of latus rectum of the parabola.Ex 7.1 Q1(i)
- Ex 7.1 Q1(ii)
- Ex 7.1 Q1(iii)
- Ex 7.1 Q1(iv)
- Ex 7.1 Q1(v)
- Ex 7.1 Q2Find the equation of the parabola with vertex at the origin, axis along Y-axis and passing through the point .
- Ex 7.1 Q3Find the equation of the parabola with vertex at the origin, axis along X-axis and passing through the point .
- Ex 7.1 Q4Find the equation of the parabola whose vertex is O and focus at .
- Find the equation of the parabola with vertex at the origin, axis along X-axis and passing through the point.Ex 7.1 Q5(i)
- Ex 7.1 Q5(ii)
- For the parabola , find the parameter of the point.Ex 7.1 Q6(i)
- Ex 7.1 Q6(ii)
- Ex 7.1 Q7Find the focal distance of a point on the parabola whose ordinate is 2 times the abscissa.
- Find coordinate of the point on the parabola. Also find focal distance.Ex 7.1 Q8(i)whose parameter is
- Ex 7.1 Q8(ii)whose parameter is
- Ex 7.1 Q9For the parabola , find the coordinate of the point whose focal distance is 17.
- Ex 7.1 Q10Find length of latus rectum of the parabola passing through the point .
- Ex 7.1 Q11Find the area of the triangle formed by the line joining the vertex of the parabola to the end points of latus rectum.
- Ex 7.1 Q12If a parabolic reflector is 20 cm in diameter and 5 cm deep, find its focus.
- Ex 7.1 Q13Find coordinate of focus, vertex and equation of directrix and the axis of the parabola .
- Find the equation of tangent to the parabola.Ex 7.1 Q14(i)from the point
- Ex 7.1 Q14(ii)from the point
- Ex 7.1 Q15If the tangent drawn from the point to the parabola are perpendicular to each other, find .
- Ex 7.1 Q16Two tangents to the parabola meet the tangents at the vertex in the point P and Q. If PQ , prove that the equation of the locus of the point of intersection of two tangent is .
- Ex 7.1 Q17Find the equation of common tangent to the parabola and .
- Ex 7.1 Q18Find the equation of the locus of a point, the tangents from which to the parabola are such that some of their slopes is .
- Ex 7.1 Q19The tower of a bridge, hung in the form of a parabola have their tops 30 meters above the road way and are 200 meters apart. If the cable is 5 meters above the road way at the centre of the bridge, find the length of the vertical supporting cable from the centre.
- Ex 7.1 Q20A circle whose centre is passes through the focus of the parabola . Show that the circle touches the directrix of the parabola.
7.2 Ellipse
6 q
Solved Examples
Worked · 6
- Find the coordinates of the foci, the vertices, the length of major axis, the eccentricity and the length of the latus rectum of the ellipse7.2.2 SolvedEx.1(i)
- 7.2.2 SolvedEx.1(ii)
- 7.2.2 SolvedEx.1(iii)
- 7.2.2 SolvedEx.1(iv)
- 7.2.2 SolvedEx.2Find the equation of an ellipse having vertices and foci
- 7.2.2 SolvedEx.3Find the eccentricity of an ellipse whose length of the latus rectum is one third of its minor axis.
7.2 Tangents and the Auxiliary Circle
4 q
Solved Examples
Worked · 4
- Find the equation of tangent to the ellipse7.2.8 SolvedEx.1(i)at the point .
- 7.2.8 SolvedEx.1(ii)at the point whose eccentric angle is .
- 7.2.8 SolvedEx.2Show that the line is tangent to the ellipse .
- 7.2.8 SolvedEx.3Find the equations of tangents to the ellipse passing through the point .
Exercise 7.2
35 q
- Find the (i) lengths of the principal axes. (ii) co-ordinates of the focii (iii) equations of directrics (iv) length of the latus rectum (v) distance between focii (vi) distance between directrices of the ellipse:Ex 7.2 Q1(a)
- Ex 7.2 Q1(b)
- Ex 7.2 Q1(c)
- Ex 7.2 Q1(d)
- Find the equation of the ellipse in standard form ifEx 7.2 Q2(i)eccentricity and distance between its focii .
- Ex 7.2 Q2(ii)the length of major axis 10 and the distance between focii is 8.
- Ex 7.2 Q2(iii)distance between directrix is 18 and eccentricity is .
- Ex 7.2 Q2(iv)minor axis is 16 and eccentricity is .
- Ex 7.2 Q2(v)the distance between foci is 6 and the distance between directrix is .
- Ex 7.2 Q2(vi)The latus rectum has length 6 and foci are .
- Ex 7.2 Q2(vii)passing through the points and
- Ex 7.2 Q2(viii)the dist. between its directrix is 10 and which passes through
- Ex 7.2 Q2(ix)eccentricity is and passes through .
- Ex 7.2 Q3Find the eccentricity of an ellipse, if the length of its latus rectum is one third of its minor axis.
- Ex 7.2 Q4Find the eccentricity of an ellipse if the distance between its directrix is three times the distance between its focii.
- Ex 7.2 Q5Show that the product of the lengths of ht perpendicular segments drawn from the foci to any tangent line to the ellipse is equal to 16.
- Ex 7.2 Q6A tangent having slop to the ellipse intersects the X and Y axes in the points A and B respectively. If O is the origin, find the area of the triangle.
- Ex 7.2 Q7Show that the line is a tangent to the ellipse . Find the point of contact.
- Ex 7.2 Q8Show that the line touches the ellipse . Find the point of contact.
- Ex 7.2 Q9Determine whether the line is a tangent to the ellipse . If so, find the co-ordinates of the pt of contact.
- Ex 7.2 Q10Find k, if the line touches .
- Find the equation of the tangent to the ellipseEx 7.2 Q11(i)passing through the point .
- Ex 7.2 Q11(ii)from the pt .
- Ex 7.2 Q11(iii)from the point .
- Ex 7.2 Q11(iv)which are parallel to the line .
- Ex 7.2 Q11(v)which are parallel to the line .
- Ex 7.2 Q11(vi)which are to the line .
- Ex 7.2 Q11(vii), to the line .
- Ex 7.2 Q12Find the equation of the locus of a point the tangents form which to the ellipse are at right angles.
- Ex 7.2 Q13Tangents are drawn through a point P to the ellipse having inclinations and such that . Find the equation of the locus of P.
- Ex 7.2 Q14Show that the locus of the point of intersection of tangents at two points on an ellipse, whose eccentric angles differ by a constant, is an ellipse.
- Ex 7.2 Q15P and Q are two points on the ellipse with eccentric angles and . Find the equation of the locus of the point of intersection of the tangents at P and Q if .
- Ex 7.2 Q16The eccentric angles of two points P and Q the ellipse differ by . Show that the locus of the point of intersection of the tangents at P and Q is the ellipse .
- Ex 7.2 Q17Find the equations of the tangents to the ellipse , making equal intercepts on co-ordinate axes.
- Ex 7.2 Q18A tangent having slope to the ellipse intersects the X and Y axes in the points A and B respectively. If O is the origin, find the area of the triangle.
7.3 Hyperbola
4 q
Solved Examples
Worked · 4
- Find the length of transverse axis, length of conjugate axis, the eccentricity, the co-ordinates of foci, equations of directrices and the length of latus rectum of the hyperbola7.3.3 SolvedEx.1(i)
- 7.3.3 SolvedEx.1(ii)
- 7.3.3 SolvedEx.2Find the equation of the hyperbola with the centre at the origin, transverse axis 12 and one of the foci at
- 7.3.3 SolvedEx.3Find the equation of the hyperbola referred to its principal axes whose distance between directrices is and eccentricity is .
7.3 Tangents and Asymptotes
4 q
Solved Examples
Worked · 4
- 7.3.9 SolvedEx.1Find the equation of the tangent to the hyperbola at a point in the third quadrant whose abscissa is .
- 7.3.9 SolvedEx.2Show that the line touches the hyperbola . Find the co-ordinates of the point of contact.
- 7.3.9 SolvedEx.3If the line is tangent to the hyperbola then find the value of .
- 7.3.9 SolvedEx.4The line touches the hyperbola whose foci are . Find the equation of the hyperbola.
Exercise 7.3
31 q
- Find the length of transverse axis, length of conjugate axis, the eccentricity, the co-ordinates of foci, equations of directrices and the length of latus rectum of the hyperbola.Ex 7.3 Q1(i)
- Ex 7.3 Q1(ii)
- Ex 7.3 Q1(iii)
- Ex 7.3 Q1(iv)
- Ex 7.3 Q1(v)
- Ex 7.3 Q1(vi)
- Ex 7.3 Q1(vii)
- Ex 7.3 Q1(viii)
- Ex 7.3 Q1(ix)
- Ex 7.3 Q1(x)
- Ex 7.3 Q2Find the equation of the hyperbola with centre at the origin, length of conjugate axis 10 and one of the foci .
- Ex 7.3 Q3Find the eccentricity of the hyperbola, which is conjugate to the hyperbola .
- Ex 7.3 Q4If and are the eccentricities of a hyperbola and its conjugate hyperbola respectively, prove that
- Find the equation of the hyperbola referred to its principal axes.Ex 7.3 Q5(i)whose distance between foci is 10 and eccentricity .
- Ex 7.3 Q5(ii)whose distance between foci is 10 and length of conjugate axis 6.
- Ex 7.3 Q5(iii)whose distance between directrices is and eccentricity is .
- Ex 7.3 Q5(iv)whose length of conjugate axis and passing through .
- Ex 7.3 Q5(v)which passes through the points and .
- Ex 7.3 Q5(vi)whose vertices are and end points of conjugate axis are .
- Ex 7.3 Q5(vii)whose foci are at and eccentricity .
- Ex 7.3 Q5(viii)whose length of transverse and conjugate axis are 6 and 9 respectively.
- Ex 7.3 Q5(ix)whose length of transverse axis is 8 and distance between foci is 10.
- Find the equation of the tangent to the hyperbola.Ex 7.3 Q6(i)at the point .
- Ex 7.3 Q6(ii)at the point .
- Ex 7.3 Q6(iii)at the point whose eccentric angle is .
- Ex 7.3 Q6(iv)at the point in a first quadratures whose ordinate is 3.
- Ex 7.3 Q6(v)at the point L of latus rectum in the first quadrant.
- Ex 7.3 Q7Show that the line is tangent till the hyperbola . Also find the point of contact.
- Ex 7.3 Q8If the touches the hyperbola then find the value of .
- Ex 7.3 Q9Find the equations of the tangents to the hyperbola making equal intercepts on the co-ordinate axes.
- Ex 7.3 Q10Find the equations of the tangents to the hyperbola which are parallel to the line .
Miscellaneous Exercise 7
56 q
(I) Select the correct option
Practice · 20
- Misc I Q1The line is tangent to the parabola if is
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- Misc I Q2The length of latus rectum of the parabola is
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- Misc I Q3If the focus of the parabola is its directrix is then its equation is
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- Misc I Q4The coordinates of a point on the parabola whose focal distance is 4 are
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- Misc I Q5The end points of latus rectum of the parabola are
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- Misc I Q6Equation of the parabola with vertex at the origin and diretrix is
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- Misc I Q7The area of the triangle formed by the line joining the vertex of the parabola to the end points of its latus rectum is
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- Misc I Q8If is any point on he ellipse . S and are its foci then
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- Misc I Q9The equation of the parabola having and as end points of its latus rectum is
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- Misc I Q10If the parabola passes through then the length of its latus rectum is
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- Misc I Q11The eccentricity of rectangular hyperbola is
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- Misc I Q12The equation of the ellipse having foci and eccentricity is,
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- Misc I Q13The equation of the ellipse having eccentricity and passing through is
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- Misc I Q14If the line touches the ellipse then the value of k is
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- Misc I Q15The equation of the ellipse is . The equations of the tangents making an angle of with the major axis are
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- Misc I Q16The equation of the tangent to the ellipse which is perpendicular to the is,
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- Misc I Q17Eccentricity of the hyperbola is
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- Misc I Q18Centre of the ellipse is at
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- Misc I Q19If the line touches the hyperbola , the point of contact is
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- Misc I Q20The foci of hyperbola are
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(II) Answer the following
Practice · 36
- For each of the following parabolas, find focus, equation of the directrix, length of the latus rectum, and ends of the latus rectum.Misc II Q1(i)
- Misc II Q1(ii)
- Find the Cartesian co-ordinates of the points on the parabola whose parameters areMisc II Q2(i)2
- Misc II Q2(ii)
- Misc II Q3Find the co-ordinates of a point of the parabola having focal distance 10.
- Misc II Q4Find the equation of the tangent to the parabola at the point on it.
- Misc II Q5Find the equation of the tangent to the parabola at on it.
- Misc II Q6Find the equations of the tangents to the parabola through the point .
- Misc II Q7Show that the two tangents drawn to the parabola from the point are at the right angle.
- Misc II Q8Find the equation of the tangent to the parabola which is parallel to the line . Find its point of contact.
- Misc II Q9A line touches the circle and the parabola . Show that its equation is .
- Misc II Q10Two tangents to the parabola meet the tangent at the vertex in P and Q. If , prove that the locus of the point of intersection of the two tangents is .
- The slopes of the tangents drawn from P to the parabola are and , show that, where k is a constant.Misc II Q11(i)
- Misc II Q11(ii)
- Misc II Q12The tangent at point P on the parabola meets the axis in Q. If S is the focus, show that SP subtends a right angle at Q.
- Find the (i) lengths of the principal axes (ii) co-ordinates of the foci (iii) equations of directrices (iv) length of the latus rectum (v) Distance between foci (vi) distance between directrices of the curveMisc II Q13(a)
- Misc II Q13(b)
- Misc II Q13(c)
- Misc II Q13(d)
- Find the equation of the ellipse in standard form ifMisc II Q14(i)eccentricity and distance between its foci .
- Misc II Q14(ii)the length of major axis 10 and the distance between foci is 8.
- Misc II Q14(iii)passing through the points and .
- Misc II Q15Find the eccentricity of an ellipse if the distance between its directrices is three times the distance between its foci.
- Misc II Q16For the hyperbola , prove that , where S and are the foci and A is the vertex.
- Misc II Q17Find the equation of the tangent to the ellipse passing through the point .
- Misc II Q18Find the equation of the tangent to the ellipse at .
- Misc II Q21Show that the product of the lengths of its perpendicular segments drawn from the foci to any tangent line to the ellipse is equal to 16.
- Find the equation of the hyperbola in the standard form ifMisc II Q22(i)Length of conjugate axis is 5 and distance between foci is 13.
- Misc II Q22(ii)eccentricity is and distance between foci is 12.
- Misc II Q22(iii)length of the conjugate axis is 3 and distance between the foci is 5.
- Find the equation of the tangent to the hyperbola,Misc II Q23(i)at
- Misc II Q23(ii)at
- Misc II Q23(iii)at .
- Misc II Q24Show that the line touches the hyperbola . Find the point of contact.
- Misc II Q25Find the equations of the tangents to the hyperbola which are perpendicular to the line
- Misc II Q26Two tangents to the hyperbola make angles , , with the transverse axis. Find the locus of their point of intersection if .